The present invention relates to the field of air sampling systems, and more particularly to an automatic air sampling system that is useful for remotely sampling air from an isolated container-filling machine to assess the possibility of microbial contamination.
Isolated filling machines (isolators) are used in the pharmaceutical industry for sterile automated filling of pharmaceutical containers. Due to the sterility requirements of the isolator, objects passing into and out of the isolator must go through a cumbersome sterile “rapid” transfer port (RTP). This conventional sterile port arrangement greatly complicates the process of handling air monitoring equipment and materials that are required to determine air quality within the isolator.
Isolator space is very limited primarily because the only easy access is through fixed glove ports that have predetermined locations and limited reach. These glove ports have been provided so that an operator is able to perform routine clean up and sanitization between lots without opening the isolator and breaking its sterility. The arm length gloves are permanently installed in the isolator housing. Since operators have only limited movement and reach, many isolators have been designed in a “balcony” layout with nearly no horizontal flat surfaces inside the sterile manufacturing space. Accordingly, there is little space available for air monitoring equipment within the isolator.
Currently to test for microbial contamination, a technician must manually pass an agar filled Petri dish or settling jar into an isolator through the sterile transfer ports. The technician then opens the dish through the gloved ports and times its exposure within the isolator. The technician then covers the dish through the gloved ports, removes it from the isolator through the sterile transfer ports and transports the dish to an incubator for growth promotion. This cumbersome task may be performed repeatedly thought each day. When it is performed, great care must be taken to avoid disturbing the normal airflow patterns inside the isolator if representative results are to be expected.
Since operators are required to place their hands into close proximity with moving machinery, access to most of the glove ports is limited to times when the filling equipment inside the isolator is not running. Thus, the filling machine must be shut down during this activity for the safety of the technician. Further, the introduction of a growth media into the sterile isolator is problematic, since the growth media could be spilled within the isolator and contribute to the growth of undesired contaminants. The growth media can also come in contact with the gloves and be transferred to other areas of the isolator as the gloves are used to make normal adjustments and perform other tasks.
Therefore, a principal object of this invention is to provide a convenient method and means for collecting a gas sample from within an isolator, then remotely and automatically exposing it to media in a sample container outside the isolator so as to test the gas sample for microbial growth.
Another object of the invention is to provide a highly automated method and means for exposing media in sample containers to the gas sample such that fresh sample containers can be supplied and exposed sample containers can be removed without interrupting ongoing exposure of sample containers.
A further objective of the present invention is to provide a method and means designed for long periods of “unattended operation”, and which requires only periodic maintenance to program cycles on the controller and to supply fresh sample containers and pick up the exposed containers.
A further object of the invention is to provide a highly automated method and means for processing sample containers wherein the first fresh container supplied is the first exposed container removed for testing.
An additional object of the invention is to provide a convenient platform for particulate monitoring, and for monitoring for concentrations of flammable or explosive gases, in the isolator as a part of the system.
These and other objects will be apparent to those skilled in the art.